The present invention relates to a circuit for a sensor the output signal of which is dependent on the temperature as well as on the variable to be measured.
For the determination of different physical variables, for instance a pressure, a magnetic field strength or a velocity of flow, sensors are known which supply an electrical output signal which is analogous to the physical variable. However, the output signal is frequently dependent not only on the variable to be determined but also on the temperature. This temperature-dependence consists generally in the fact that, on the one hand, the sensitivity of the sensor, and therefore the change in the output signal upon a given change in the variable to be determined, and, on the other hand, an additive component (so-called offset) are dependent on the temperature. In this connection there are differences between the individual manufactured sensors of the same type so that, upon the use of the sensors, circuits which provide compensation for the temperature errors are necessary, the degree of the specific compensation being adjustable. In the circuits known up to the present time, however, the adjustments have mutually affected each other so that an iterative and thus time-consuming procedure was necessary for the compensation.
It is an object of the present invention to provide a circuit for a sensor which permits of independent adjustment of the compensation for the temperature error of the sensitivity and offset.